1. Field of the Invention
The present invention relates to a method for performing location update in various manners when a mobile station travels between paging groups in a wireless access system.
2. Discussion of the Related Art
Hereinbelow, a paging group and an idle mode of a mobile station (MS), which are associated with embodiments of the present invention, will be described in brief.
FIG. 1 illustrates an example of paging groups each consisting of a plurality of base stations (BSs).
Paging refers to a function for discerning the location (e.g., any BS or any switching station) of a corresponding MS, upon occurrence of an incoming signal in mobile communication. As illustrated in FIG. 1, a plurality of BSs supporting an idle mode may belong to a paging group to construct a paging area.
At this time, the paging group indicates a logical group. The paging group provides an adjacent range area which can be paged through a downlink when traffic targeting an MS is present. It is desirable that the paging group be large enough to accommodate specific MSs within the same paging group during most of the time and be sufficiently small to maintain a paging load at a proper level.
FIG. 1 shows 4 paging groups defined in multiple BSs located on hexagonal lattices. One BS may be contained in one or more paging groups. The paging group is defined in a management system. The paging group may use paging group action backbone network messages. A paging controller may manage a list of an idle-mode MS using a paging-announce message which is one of the backbone network messages and may manage initial paging of all BSs belonging to the paging group.
An idle mode refers to an operation which supports periodic transmission of downlink broadcast traffic of a BS without being registered in a specific BS when the MS travels in a wireless link environment comprised of multiple BSs.
The idle mode may be of benefit to an MS by eliminating activation requests related to handover and general operation requirements. The idle mode limits activation of the MS to be scanned during a discrete period, thereby reducing power consumption and operation resources used by the MS.
Furthermore, the idle mode may provide a simple and proper method which is capable of informing the MS of pending downlink traffic and may be helpful to a network and a BS by eliminating a wireless interface and network handover traffic from an inactive MS.